Refrigeration



1949 H. K. BERGHOLM 2,490,401

REFRIGERATION Filed Aug. 25, 1944 ,4; ATTORNEY Patented Dec. 6, 1949 REFRIGERATION Harry Karl Bersholm, Stora Essingen, Sweden, assignor to Aktiebolaget Elektrolux, Stockholm, Sweden, a corporation of Sweden Application August 25, 1944, Serial No. 551,111 In Sweden October 8, 1943 '6 Claims. (Cl. 62-1195) The present invention relates to a method of utilizing, in air-cooled absorption refrigerating apparatus, the condensate precipitated in the pressure-equalizing vessel, for the purpose of generating cold. The invention has for its object to make possible such a placing of the condenser system, inclusive of the pressure-equalizing Vessel, in relation to the other parts of the apparatus, more particularly the evaporator, that the mounting of the refrigerating apparatus in the cooling air shaft generally arranged on one side of the refrigerator cabinet operated by the apparatus will be simple and suitable. Especially does the invention design to facilitate a suitable placing of the pressure-equalizing vessel of the apparatus, without it being necessary to return refrigerant condensate precipitated in said vessel to the circulation system of the absorption solution without having been utilized for useful generation of cold.

It is generally known that the placing of the condenser and the pressure-equalizing vessel, said two apparatus parts forming together the condenser system of the apparatus, relatively to the other apparatus parts, more particularly the evaporator, ofiers considerable dimculties, because the pressure-equalizing vessel, at least in large apparatus, should preferably have the shape of a broad tube closed at both ends and have substantially the same length as the width of the refrigerator cabinet. The pressure-equalizing vessel must be so placed that it does not influence in too unfavorable a manner the flow of the cooling air, and at the same time it is highly desirable that it should be located beneath the upper edge of they refrigerator cabinet. As, on the other hand, the evaporator should, for practical reasons, be placed as near the roof of the cooling space as possible, it is obvious that the height of fall from the pressure-equalizing vessel and the condenser generally placed beneath said vessel to the evaporator will be very low. It has therefore been proposed to place the condenser beneath the inlet of the evaporator and use boiler vapors for boiling off the condensate, the vapour generated being used for boiling off and thus raising liquid to the evaporator. In other cases the pressureequalizing vessel has been placed beneath the condenser, in which case, however, it has been necessary to let the condensate precipitated under certain operating conditions into said vessel flow back to the liquid circulating system of the apparatus, without being utilized. According to the present invention any condensate precipitated in the condenser system is utilized for useful genboiler vapours into a storage vessel intended for condensate precipitated in the pressure-equalizing vessel and communicating with a liquid pump, the vapours being thus caused to raise the condensate to such a high level that the refrigerant will flow from thence by itself into the evaporator. According to another embodiment of the invention the vapour flowing from the boiler to the condenser is used for this purpose, the vapour being led into the condensate and thereby, by direct thermosiphon action, raising the liquid to the evaporator.

The invention will in the following be more fully described with reference to the embodiment shown diagrammatically in the accompanying drawing from which also other characteristic features of the invention will be seen.

The single figure shows diagrammatically an absorption refrigerating apparatus operating with a pressure-equalizing gas, such as hydrogen gas, and having ammonia and water for other operating media. The boiler of the apparatus is designated by it and is provided with a thermosiphon pump 6 i by which the solution rich in refrigerant and flowing from the absorber vessel 52 of the ap paratus through a liquid heat exchanger it is raised to the intended boiler level. The com denser of the apparatus is designated by it, and may preferably be air-cooled, as is also the case with the absorber l 5 of the apparatus formed by a tube coil with or without cooling flanges. The poor solution formed in the boiler ill flows through a conduit I 6, the outer jacket of the heat exchanger l3 and a conduit ll into the absorber eration of cold, which is efiected chiefly by leading IS. The circulation system of the absorption solution is thus built up in a manner known per se.

The vapor generated in the boiler is led through a conduit is preferably provided with a rectifier 30 to a pump vessel I9 which, in the embodiment shown, consists of a relatively broad tube which is closed at both ends and in the middle part of which is arranged a partition 20 dividing the pump vessel into an upper and lower chamber. These chambers communicate with each other by a "pump tube 2| which, below, is preferably pro-' vided with one or more small holes 22 intended to facilitate the pumping action. If it is assumed to begin with that the pump vessel l9 does not contain any liquid, the boiler vapours will flow through the pump tube 2! into the upper chamber from which the vapour flows further to the condenser ld. The condensate formed therein flows through a conduit 23 into the pressure-equalizing vessel 25 of the apparatus formed in known manner with a ventilating conduit 28 and a drain conduit 2'. The mode of working of the pressureequallzing vessel is known per se. The condensate flows through the drain conduit 25 into the lower part of the pump vessel It in which the liquid level gradually rises above the hole 22. The continuously inflowing vapour pumps up liquid through the pump tube 2i, so that the liquid level above the partition it rises sufliciently for the liquid refrigerant to flow through a conduit 21 into the evaporator of the apparatus designated by 28. The evaporator is formed as a tube coil and, in a manner known per se, connected via a gas heat exchanger 29 with the gas circulation system of the apparatus. The connection is so arranged that the gas poor in refrigerant vapours and coming from the absorber l5 flows through the evaporator coil in counter-current to the downflowing refrigerant. I

As is well known, there ensues in pressureequalizing vessels of absorption refrigerating apparatus under certain operating conditions a condensation of refrigerant vapours, as when their partial pressure in the inert gas surpasses certain values. It is, however, obvious that, in the embodiment shown, not only the refrigerant condensate coming from the condenser is but also the condensate precipitated in the pressure vessel 24 will, with the help of the boiler vapours, be fed into the evaporator, thus being of use to the production of cold if desired. It is possible to connect the conduit 23 direct with the evaporator, because the condenser is located sufllciently high relatively to the latter. It is, however, as a rule advantageous to let also the refrigerant from the condenser pass through the pump 2|, as this will enable the pump to operate under more uniform conditions, which is of great advantage in the case of heat-operated pumps of the kind referred to.

Under certain conditions the pressure-equalizing vessel 24 and the condenser It may have their places changed, so that the former will be located higher than the evaporator, while the condenser will be located lower than the latter. Such a placing of said apparatus parts is, however, as a rule less advantageous than the arrangement shown in the drawing.

The invention is not limited to the embodiment shown, but may be modified in several ways, without departing from the spirit of the invention.

I claim:

1. In the art of refrigeration with the aid of a system in which refrigerant evaporates in the presence of an inert gas to producea refrigerating effect at a place of evaporation in a circuit for such gas and refrigerant vapor is generated at a place of vapor expulsion, such system having a space for normally holding a reserve supply of inert gas which is in communication with the gas circuit and in which condensation of refrigerant vapor is effected, the improvement which comprises deriving useful refrigeration from condensate in said space by utilizing vapor from the place of vapor expulsion to raise such condensate by vapor lift action to a higher-level, and flowing raised condensate by gravity to the place of evaporation.

2. In the art of refrigeration with the aid of a system in which refrigerant evaporates in the presence of an inert gas to produce a refrigerating effect at a place of evaporation in a circuit for such gas and such refrigerant is conducted to the place of evaporation from a place of condensation to which refrigerant vapor flows in a path of flow from a place of vapor expulsion, such reserve supply of inert gas which. is in communication with the gas circuit and the place of condensation and in which condensation of refrigerant is effected, the improvement which comprises deriving useful refrigeration from liquid refrigerant condensed in said space by utilizing vapor from the place of vapor expulsion to raise such liquid in said path of flow by vapor lift action to a higher level, and flowing raised liquid by gravity to the place of evaporation.

3. An absorption refrigerating system of the inert gas type comprising a circuit for inert gas including an evaporator, a generator for gencratingrefrigerant vapor, a condenser in which refrigerant vapor from said generator is liquefied, a pressure equalizing vessel for holding a reserve supply of inert gas which is connected to said condenser and to the gas circuit and in which condensation of refrigerant vapor is effected, and structure for using condensate in said vessel to produce useful refrigeration comprising conduit means including a vapor lift which is connected to receive refrigerant vapor from said generator and condensate from said vessel and through which condensate is raised upwardly by vapor lift action to a higher level, said conduit means providing a path of flow for conducting raised condensate by gravity to said evaporator.

4. An absorption refrigerating system of the inert gas type comprising an inert gas circuit including an evaporator, an absorption liquid circuit including a generator for generating refrigerant vapor, a condenser connected to receive refrigerant vapor from said generator, a pressure equalizing vessel for holding a reserve supply of inert gas which is connected to said condenser and to the gas circuit and in which condensation of refrigerant vapor is effected, structure for using condensate in said vessel to produce useful refrigeration including a vapor lift for conducting such condensate to said evaporator, and conduit means including a rectifier for conducting refrigerant vapor from said generator to said vapor lift for operating the latter.

5. An absorption refrigerating system of the inert gas type comprising an inert gas circuit including an evaporator having an inlet for liquid refrigerant, a circuit for absorption liquid including a generator for expelling refrigerant vapor, anair cooled condenser providing a fluid passageway having an inlet at one level and an outlet at a lower level below the liquid inlet of said evaporator, the lower part of said passageway being connected to said gas circuit and constructed and arranged to provide a chamber for holding a reserve supply of inert gas, and conduit means for flowing refrigerant vapor from said generator to the inlet of said passageway in which the vapor is cooled and condensed, said conduit means including a vapor lift connected to' the outlet of said passageway to receive condensate formed in said condenser and through which refrigerant vapor from said generator raises such condensate to a higher level for gravity flow to the liquid inlet of said evaporator.

' 6. An absorption refrigerating system of the inert gas type comprising a gas circuit including an evaporator having an inlet for liquid refrigerant, a generator for producing refrigerant vapor, a condenser, a pressure equalizing vessel for holding a reserve supply of inert gas which is disposed at a lower level than said condenser and connected thereto and to the gas circuit, and

means providing a chamber which is connected REFERENCES CITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Ullstrand Mar. 12, 1935 Ashby Sept. 13, 1938 Bergholm Dec. 16, 1941 Nelson Feb. 3, 1942 Siedle Nov. 12, 1944 Reistad Jan. 25, 1945 Coons Oct. 9, 1945 

